This invention relates to insulated pipe jacketing accessories and, more particularly, to a rain shielding accessory for preventing deterioration of jacketed pipes and/or pipe insulation as a result of water concentration and collection at the base of vertically-projecting pipe appendages such as hanger rods, valve stems, and the like.
Many industrial installations require extensive use of above-ground, outdoor pipe systems for handling a wide variety of fluids which are temperature sensitive in the sense that thermal insulation is required or desirable in the attainment of overall fluid handling efficiency. Insulation of such pipe systems, in turn, is most effectively accomplished by suspending each pipe in space from appropriate supports by depending rods connected to the pipe at spaced intervals along the length thereof, placing any of several acceptable insulating materials about the periphery of the pipe and covering the insulation with an impermeable jacketing material such as sheet plastic, stainless steel, fiber reinforced resin, or the like. The jacketing functions primarily to protect the insulation from deterioration from impregnation of dust and/or water as well as from physical damage.
Jacketing systems are available which are highly effective for encapsulation of pipe insulation and which are capable of application with relative ease to cylindrical lengths of pipe as well as to the various fittings conventionally used in pipe systems such as L's, T's, valve bodies, and the like. Various types of sheet plastic jacketing systems are particularly suited to this application because of the facility offered by such material for an hermetic seal by solvent welding and the general capability of the material to provide weather-proof encapsulation of insulated pipes and fittings.
With all such available insulation jacketing, particularly in outdoor pipe installations, a serious problem is presented by the presence of vertically-projecting pipe appendages such as hanger rods, valve stems, and the like. Such pipe appendages must project through the insulation and jacketing in a way so as to require a caulking-like sealant between the stem or rod and the pipe jacketing in order to effect a complete hermetic seal. Such sealants, however, even with regular maintenance, deteriorate with age and exposure to result in a leakage point in the context of the overall hermetic seal provided by the jacketing. Moreover, because of the location of the caulking-type seal at the base of the vertically-extending rod or valve stem, the point of leakage is most vulnerable to water running down the surface of the rod or valve stem. As a result of this problem, serious damage is caused both to the insulation underlying the jacketing, components entrained in the insulation, and often to the pipe itself. The wetting of insulation in the base of hanger rods, valve stems, and the like, can require replacement of insulation as often as once a year in many industrial installations. Also, because of the toxic nature of the atmosphere in which industrial pipe systems are used, rain water can become sufficiently corrosive to damage the pipe itself, particularly in the concentrated area underlying a suspension rod, for example. In other types of installations where electrical tracers are embedded in the insulation, the tracers are severely damaged so as to require replacement on a regular basis.
In light of the foregoing, it will be appreciated that there is need for an acceptable solution to the problems associated with leakage of pipe insulation jacketing in the region of hanger rods, valve stems, and the like.